Plug adapter



FIG. 1 is a top, back perspective view of a plug adapter;

FIG. 2 is a top, front perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left-side view thereof;

FIG. 6 is a right-side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The dash broken lines depict portions of the plug adapter that form no part of the claimed design. 

CLAIM The ornamental design for a plug adapter, as shown and described. 